some frosty nights also. more that some frosty nights also. more updates in 30 minutes. hello, this is bbc news. the headlines at 8.30. the headlines at 8.30. at least 43 people have died in syria, after a huge car bomb exploded on the outskirts of aleppo. thousands of people from two besieged government—held towns were waiting to be transported under the terms of an evacuation deal. north korea warns the us not to take provocative action in the region, saying it is "ready to hit back with nuclear attacks". the comments came as north korea marks the 105th anniversary of the birth of its founding president, kim il—sung. everton bans sun journalists from its stadium and training ground, following a column by kelvin mackenzie regarding midfielder ross barkley. delegates at the nut conference vote in favour of a ballot on strike action in england, because of concerns about funding cuts. now on bbc news, weather world, and this time nick miller and sarah keith—lucas have been

to northern ireland to look at the relationship between aviation and the weather. this time on weather world we are in northern ireland, airside at belfast international airport. we're going behind the scenes to find out what it takes to keep these planes flying and you and i safe, whatever the weather. also on weather world, devastation and deadly floods in south america. but some dramatic escapes too after months of heavy rain leave towns under water. and mud. as landslides kill hundreds. weather bomb, the storms so strong they hold a unique place in weather science. and have taken california from drought to deluge,

with the ground giving way. and extreme heat. wild fires, as parts of australia endure their hottest summer. plus: you have some history there. taking the temperature. i will be opening the archives of one of the world's longest running weather observations and watching how it's still being done today. i will be taking a trip back to my own family history and aviation‘s past, to see how some of today's technology was born. welcome to weather world at belfast international airport. 13 miles north—west of the city of belfast, this site was first established as a military base in the first world war. since then, it's grown to become the busiest airport in northern ireland, with overfive million passengers travelling through it last year. the airport serves other uk and european destinations,

plus there are flights to the usa. weather and airports. so much can go wrong, can't it? it's an interesting relationship — thunder storms, fog, wind, snow. someone that knows all about those weather challenge is michael cockcroft, the general manager of air traffic control here. hello, michael. hi. is there a day when you are not thinking about the weather? no, every day, every day controllers come into work, they're obviously always thinking about the weather. the surface wind is very important, in terms of deciding what's the direction of runway for take—off and landing. interested in the cloud, the type of precipitation falling, whether it's rain, heavy rain or drizzle. and also down to fog, all affects flights nd flight safety. so we are very interested in knowing all we need to about that. there is something specific about the airport here at belfast which is about the weather and increases your flexibility. yeah, we are one of the only remaining uk airports that still operates a cross runway. so our main runway faces west — east—west orientation. we also have a cross runway, 1735, which sits at right angles from the main runway.

it's orientated more or less north—south. we tend to find, during the autumn when we get low pressures coming across the atlantic we get strong southerly gales, and a pilot's preference is is to land into wind, so when the cross wind gets roughly around 25—30 knots, the pilots will opt to take runway 17 for a safer approach and take—off. so weather is so important and sarah's in the control tower now to take a look at how they get the very latest weather information here. this is the main weather system used here in the air traffic control centre. all the numbers and figures on the screen correspondent to continuous weather data that's collected. we record things like wind direction and speed, visibility, any significant weather around, as well as importantly cloud amounts and heights too. every half an hour a report is issued.

that will help pilots make operational decisions about whether it is safe to land or whether they might need to divert to another airport. when the weather gets rough, the landings get tough. this plane struggles to maintain a steady approach to manchester airport in february, in the uk's fourth named storm of the season. winds of up to ioomph hit the uk as storm doris blows in. as you see the foam hitting me from the sea, that it definitely has materialised, gusts here are so powerful i can't even face in the direction the wind is coming from. as reporters tried to remain upright, some trees failed. a lucky escape here for a driving instructor. but the storm did claim the life of a woman hit by falling debris, and it wasn't just the wind doing the damage. there was heavy snow too, here in scotland. storm doris was an area of low pressure that underwent explosive cyclogenesis, deepening rapidly, so strengthening quickly. storms like this have become known as weather bombs. snow emergency.

that life—threatening storm pummelling the north—east right now... this was another. a major snow storm hits the north—east usa in march, bringing to an abrupt end what had been a mild start to the year. and for the first time in 33 years in new york, march was colder than february. there is cold and there is frozen solid. this house became encased in ice after strong winds blew water from lake ontario over it, which then froze. amazingly, when the ice melted, these pictures show the house emerging virtually unscathed. europe's coldest winter month was january. with the unusual sight of snow on greek island beaches. but the bitterly cold weather brought fresh misery for migrants at camps such as these in the balkans. then, disaster in italy.

a mountain hotel buried by an avalanche. 29 people are killed, but amazingly, some survive, rescued more than two days later. oh my god! tornado season in the usa peaks in spring, but this is february in louisiana. and new olleans is hit with its strongest tornado on record. and new orleans is hit with its strongest tornado on record. but worst came even earlier. a january outbreak of tornado sweeps through south—eastern states, leaving total devastation and 20 dead. more than died in tornados in the usa in the whole of last year. it's a beautiful day here at belfast international airport today, but visibility is not always this good. in fact, the airport can be prone to seeing pretty dense fog. michael is going tojoin me now, and can you explain just how do

you land a plane when you can't see the runway? certainly. we have an instrument landing system at the airport, part of that system is the glide path. it sends a signal in space to the pilot and tells him if he is too high or too low as he makes the approach. we have another signal at the other end of the runway, the localiser, and it tells the pilot if he is left or right of centre line. the combination of the two, left right, up, down, safety guides the aircraft to land. wonderful. we have had a look at what it looks like from the ground, what i would love to see is how this instrument landing system works from up in the skies. shall we take a look? absolutely, let's go. michael, we are up in the air. can you explain to us a little bit about how this instrument landing system, the ils works from the pilot's perspective up here? absolutely. you can see the pilot gets the distance from touchdown. it's displayed at all times in the cockpit. so he knows how far he is from touchdown.

he is currebtly being vectored by the controller to intercept the ils. you can see from the ils signal at the moment, the needle is to the left of the centre light. that means the aircraft needs to fly left to get on track. i suppose in very poor visibility conditions, in thick fog or blowing snow, the pilot would completely rely upon this instrument? absolutely. and the system at aldergrove allows the aircraft to auto land in those sort of conditions. we took to the skies thanks to air ambulance northern ireland, but every commercial airline has an instrument landing system on board, so, no matter where in the world you make your landing, the guidance given to your pilot will be exactly the same. it takes an awful lot of power to power the ils, all this kit, and also an entire airport, but you might be surprised to hear where that power comes from. let's head down to nick on the ground to explain more. infact, sarah, belfast international airport requires 1.8 megawatts of electricity every day. and they get it right here, right next to the airport, from tens of thousands of solar panels, and on a sunny

day this gives the aerp all the power it needs. day this gives the airport all the power it needs. over here, if you listen carefully, that whiny sound is the power being made, because even though it's cloudy there is still solar energy coming through, converted form dc to ac power through this inverter. alan whiteside is the operations manager here at the airport. how important is this solar farm, and has it become to the airport? it's been a great success for us. the first nine months it produced 27% of the energy that we use on airport. it still is producing on a day like this. on a really good day absolutely everything on airport, from radars to instrument landing systems, security systems, baggage systems, everything on airport is running on it. it is still producing excess for the grid. we can see what it's been doing for the airport today

through this display unit here. the sun has come out occasionally today. yes, this shows the last 2a hours of production with it. last night, around sundown it was still producing, then it dropped off through the night period. from dawn, it's gone up. we had a rainy period here this morning. it's still producing 250, 500 kilowatts. at peak time when the sun has come out, it's producing 1500—1600 kilowatts of energy. so it's working very well. even for northern ireland. i wish you many more blue sky days. thank you very much. bbc weather watchers know cloudy days have their pluses too. and theyjust got a whole lot more interesting thanks to the release in march of an updated cloud atlas from the world meterological

organisation. it features newly classified cloud formations such as these as seen in dorset. and these dramatic undulating clouds pictured here in the peak district. still to come on weather world: michael, you have some history there. temperature tradition, more than 200 years of weather observing in ireland. i will go back to the beginning and see how it is still being done today. we have had a look at modern aviation here at belfast international airport. but now i am stepping back in time to learn a little bit more about the history and the relationship between aviation and the weather. i have a personal reason for being here today. we will look at that later on. for now, let's head inside and meet our guide ernie from the ulster aviation society. hi there, ernie. hi, sarah, it's a pleasure to welcome you. before the introduction of satellite and radar data, aircraft played a vital role in forecasting. can you tell us more about that. yes, indeed, what it involved was the aircraft of the weather

flights going out over the atlantic primarily from where most of our weather systems come, and taking a range of observations and different altitudes, observations of temperature, humidity, pressure and so on. it would have involved in some cases flights of up to eight or nine hours in length. every so often the data that was being collected would be signalled back to aldergrove. and from aldergrove it would be sent to the fraing office. why don't i interviews you to malcolm, a colleague and from aldergrove it would be sent to the forecasting office. why don't i interviews you to malcolm, a colleague who was a met observer on the weather squadron at aldergrove in the post—war period. that would be fantastic. malcolm, you were met observer on those weather flights. what was it like? a very interesting period in my life doing national service in the force. we initially had very old aircraft, the halifax, we used to be directed

by the weather forecasts, we would fly for a day into weather by the weather forecasts, we would fly for a day into where the worst weather was, find out what was really happening. as we tended to fly the majority of the flights fairly low down it could be very bumpy, very wet at the front because the aircraft used to leak a bit, being old. you could have lightning and it was a very difficult exercise for pilots and navigators to get there and back. with the poor radio waves and everything we would often be a bit of truck. it was arduous for the whole crew. ernie, i mentioned earlier that i had a personal link to this place. my grandfather was an aeronautical engineer in northern ireland for many years. can you tell me more about that? i really wanted to show you this aircraft, the short sherpa, a unique aircraft. it was built in 1953 to test the properties of a novel type of wing your grandfather designed.

a revolutionary new aircraft goes for its trials. the chief designer, david keith lucas, planned the sherpa on his drawing board and now test pilot tom brook smith looks set to continue. we are delighted it is part of the ulster aviation collection because it is a unique research aircraft and your grandfather was responsible for that. thank you so much for showing me this little bit of my family history. for now, we will be leaving these historic aircraft, and later we're heading back to belfast international airport for more on modern day aviation. now to events in southern hemisphere summer, and this from peru. if ever you need proof of the force of flood water it is here. look how the driver of this truck manages to get out just it is swept away. and again, as this hotel collapses into a flooded river. dozens of people have died in peru

since the start of the year. here is another lucky escape as a mudslide churns up the debris of what was once someone's home, a woman emerges. slowly she is able to find her feet and step to safety. the rain has been blamed on an unusually warm sea water off the coast of peru, but notjust peru has suffered. disaster in colombia, torrential rains is a mudslide torrential rains sends a mudslide into town, submerging homes, businesses and people. the death toll reaches into the hundreds. some in the area have blamed climate change for the extreme rain, others say deforestation means are more likely. mudslides are more likely. further south in chile injanuary, drought, he took, strong winds and then fire. further south in chile injanuary, drought, heat, strong

winds and then fire. this town was destroyed by wildfires said to be the worst in the modern history of the country. thousands of homes are burned to the ground. summer fires also broke out in australia, nearly 100 at one stage in february in new south wales as record high temperatures produce catastrophic fire danger. in march, the weather took a dramatic turn as cyclone debbie hit queens land and then new south wales. floods follow and after its hottest summer, sydney has its wettest margin 20 years. viewed from a helicopter, something quite astonishing is unfolding california in february. car swallowing sinkholes are appearing. there goes another. it is notjust cars disappearing, the ground is literally giving way as the state undergoes a remarkable transformation from drought with a succession of storms and weather bombs bringing flooding rain. there is so much water that the overflow from this dam

is needed for the first time in 50 years, but it fails, leading to evacuation with fears of unrestrained floodwater being sent downstream. in a world of changing climate and weather, some things change very little. like this weather ritual which has been happening for over 200 years. at 9am every day, shane kelly takes weather observations at the armagh observatory a0 miles south—west of belfast. his work and that of those before him has made this one of the longest—running series of manual weather observations in the world. shane, you have been doing this for 18 years and the temperature record goes back over 200 years. do you feel the weight of responsibility of keeping this going? it has been unbroken for 200 years, i don't want to be the one who breaks that up and becomes infamous.

it is a unique empirical record, it is a very useful record in research, schools, education for the general public. lots of weather stations are automated, what is the benefit of having you doing this every day? we had an automatic weather stations several years back, an experimental one. it broke down, sometimes you lost records. we did not lose any on the manual side. on the automatic station you were sometimes recording wind speeds of a17 mph, so you can see how an automatic station can get it wrong. do you think of the day when this might become automatic and you will not be required to do this any more? i think it will become automatic but i think the manual station will run side by side as long as there is a will for people to get up in the morning and take readings and do it every morning and keep the unbroken record.

these are those first records, safely stored at the observatory. its director michael burton is about to show me how it all began. you have some history? i certainly have, these are the first reading software i certainly have, these are the first reading of the armagh observatory. let's look at that first one. we have the logbook and we have this page at the top, these were the very first measurements made. it has held up quite well? indeed. what is it telling us? the date, the first measurement is the 27th of december 179a. we are measuring the temperature inside and outside, two thermometers, one inside the observatory and one outside in the grounds, and the barometer, the air pressure. things get more detailed over time? notes are made about significant weather events. if we can call the 19th—century the more recent past,

what happened there? 1839, the time of romley robertson, the director here for 59 years. he is recording notes, the comment says a tremendous gale in the night. there was a fantastic storm that night, it got robertson thinking about how one quantifies the strength of the wind, and a few years later he came up with the design of what we call the anemometer, which is now used the world over to measure the wind speed. one of his first models is here? on the roof of the observatory building, you can go and see it. i have an amateur weather station on my back garden and it has this on it, and to think it all started here in armagh? this is the cap anemometer, it comes from 1870, but the very basic design is how we measure wind speed the world over. it say something about design

that it has lasted the test of time? a simple design, four cups that spin in the wind, you can measure the wind speed and that is how we know wind speeds around the world. it has been fascinating seeing the weather history at the armagh observatory, thank you for showing us around. we are back at belfast international airport, and so far we have looked at how weather is pivotal to operations here and had seen some of the systems in place to deal with changeable weather conditions. i will put some about into practice and with the help of michael we will use the traffic control simulator to try to safely land a plane. imagine it is a foggy day at belfast, we have two inbound easyjets, one to the north and one to the south, we will vector them and establish them at ten miles, once they are safely established under the instrument landing system we can pretend we are transferring them to the tower.

easy 464, descent altitude 3000 feet. we record the level on the strip and we watch the radar. you can see the aircraft is starting to descend. it looks like this aircraft has safely intercepted the instrument landing system and it is on the approach to the runway? the aircraft is now approaching two miles from touchdown, he has been safely established. it is probably on a full auto land because it would be in fog and the pilots will be letting the aircraft land. that was really well done as a first attempt at vectoring an aircraft. it descended at nine miles, that is what we expected. well done, a very good first attempt. my first aircraft, safely landed. fantastic. now from our busy skies to roads,

and these iconic london cabs are far from where you would normally expect to see them. this is the arctic circle, they are being tested as they get where a 21st—century makeover with a virtually silent electric engine cutting emissions. it has been awhile since london has seen snow like this but the manufacturers hope to sell the cabs in other polluted cities like moscow, which gets a bit colder in winter. finally, we have had automobiles, planes and now trains. this is what happens when you are waiting at a station after a snowstorm, but the first train is nonstop. in march, new york commuters get a second helping of snow, but this one was not in the forecast! that is it for weather world this time from northern ireland. we will be back later in the year. until then, keep checking the forecast. let's look at that first reading.

where did i put it?! we have lost the first reading from 179a. from now onwards the first readings will be from 1795. what is going on with my hair? what is it doing? she is so polite, isn't she?! good evening. a few of the tea time showers that cropped up are fading away, but for many it has been a dry day, a lovely afternoon, similar scenes to these chap captured by a weather watcher in hertfordshire. cast your eyes to the north—west, the satellite imagery, this cloud is set to produce to the east. it producing a different day, in northern scotland a few showers on the go, temperatures dropping quickly and quickly across many eastern and southern parts of the uk, could be a touch of frost here and there, but temperatures rise

through the night after an initial dip. it is here where we could see some rain into the start of tomorrow morning, that rain will be pushing southwards and eastwards, a bit uncertainty how far north, south and how quickly that will go. it will produce a completely different day to what we have seen through today. we start dry and bright, northern scotla nd we start dry and bright, northern scotland with sunshine, but in between outbreak of cloud developing. if you are out in the afternoon this is how easter day lunchtime looks round one clock, it will be a fine day in northern scotland, other than one or two showers it should feel a touch waehler. brightening off after what could be a cloudy start. stay tune to the forecast, if your plans are weather dependent. brightening in up in northern ireland, be we cloud and rain parts of the country after a chilly start it will be a cold day. milder further south, chilly start it will be a cold day. milderfurther south, it chilly start it will be a cold day. milder further south, it should stay dry throughout. but that rain it does push towards east anglia and

the south—east during the day, slowly starting to ease as we go into the night. now as we go through night and easter monday, with low pressure to the east, we open the door to winds once again, it's a recipe for chilly winds as well, so after maybe a less cold day across western areas on sunday, monday looks chilly for many, especially where you have the cloud and a few showers that are round, pushing southwards, only form a small part of the day. out of the breeze in the sunshine it feels nice enough. lose the sunshine and it turns chilly quickly and a widespread frost in the countryside to ta ke widespread frost in the countryside to take us through monday night and into tuesday, next week we will have to get used to frosty nights, a cold air with us but away from the north of scotla nd air with us but away from the north of scotland many will have a dry week with sunny spells. bye for now.